645249051 has 8 divisors (see below), whose sum is σ = 955924560. Its totient is φ = 430166016.

The previous prime is 645249049. The next prime is 645249067. The reversal of 645249051 is 150942546.

645249051 is a `hidden beast` number, since 645 + 2 + 4 + 9 + 0 + 5 + 1 = 666.

It is not a de Polignac number, because 645249051 - 2¹ = 645249049 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 645248997 and 645249015.

It is not an unprimeable number, because it can be changed into a prime (645249001) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11949030 + ... + 11949083.

It is an arithmetic number, because the mean of its divisors is an integer number (119490570).

Almost surely, 2^645249051 is an apocalyptic number.

645249051 is a deficient number, since it is larger than the sum of its proper divisors (310675509).

645249051 is a wasteful number, since it uses less digits than its factorization.

645249051 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23898122 (or 23898116 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 36.

The square root of 645249051 is about 25401.7529119547. The cubic root of 645249051 is about 864.1234512065.

The spelling of 645249051 in words is "six hundred forty-five million, two hundred forty-nine thousand, fifty-one".